Antibody-drug conjugates (ADCs) can provide an effective means of delivering a drug to a targeted site in a tissue or organism. Recognition of a target such as a tumor by the antibody minimizes exposure of non-target tissues to toxic chemotherapeutic agents and limits adverse effects associated with the toxicity of “free” drugs (i.e., unbound to a carrier such as an antibody). ADCs can be prepared by a number of techniques. Prior to administration to a human or other subject, the conjugate is purified to remove free drugs and other impurities.
Due to the very high potency of benzodiazepine containing drugs, the removal of drug related impurities from a mixture comprising benzodiazepine ADCs and benzodiazepine drug-related impurities needs to be highly effective. The present invention addresses this and other needs.